HOWARD J
Member
I picked up a Delta the first year they came out--using factory loads it did not take long to break the slide stop--I took it back to the gun shop & traded for a 45 & never looked back.
Colt Delta Elite Recoil System
- Thread starter ugaarguy
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TexasRifleman
Moderator Emeritus
What I am getting from this, and the reason the light bulb came on for me, is that there ARE things that work against the slide to delay it a bit and weaken it's rearward movement besides the recoil spring and it just never occurred to me until these guys brought it up.
The squared off firing pin stop makes the initial movement to the rear a little harder to get started, as does the heavier mainspring by making the hammer harder to re-cock. After this initial hard start there is less energy left in the movement of the slide so you can get away with a lighter recoil spring.
That's what I'm getting from the smart guys conversation anyway. It makes complete sense now that I've seen them explain it and I hope it makes my Delta better behaved and more manageable.
Hope I understand it right, I trust they will correct me if I've misstated it.
1911Tuner
Moderator Emeritus
You do, and you didn't.
I think you'll be pleased. Be sure and let us know.
I've been using the small radius on the firing pin stop since way back before EGW started offering the ones with the square bottoms. When the small supply of originals dried up at the gun shows, I made my own.
Just for the record...again...I used them as SOP for reliability tweaks...never for recoil reduction. That they did have an effect on the way the guns behaved in recoil was a bonus, but it was never the intent.
1911Tuner
Moderator Emeritus
Now on to JERRY's point of the feeding round slowing the slide as it returns to battery...yes. That's absolutely correct. It does.
But...
It's still a standard 1911 frame and it still has a standard slidestop crosspin and it still has standard lower lug feet on the barrel. Using a 24-pound action/recoil spring still represents a 50% increase in impact momentum over the 16-pound spring...and going by the original specs...even a 16 pounds is overspringing the slide a bit.
The slide's forward momentum is essentially brought to a sudden stop by the lower lug feet hitting the slidestop pin...which in turn impacts its mounting holes in the frame. Those lower lug feet are pretty small, and the frame walls that the pin passes through are fairly thin. The lug feet can be pounded and deformed and the holes elongated earlier under 50% more more impact than they were designed to handle in the long term. It's also possible for a vertical crack to form adjacent to the bottom of the holes. I've seen it a few times in LW Commanders with as few as 5,000 rounds down the pipe from shooters using 20 pound springs in the mistaken belief that they're "saving" the frame.
The impact abutment was designed to take the impact. The lower lug feet and the slidestop holes, not so much.
Using overly strong action/recoil springs doesn't keep the gun from breaking. It only changes the place that it breaks. There just ain't any such thing as a free lunch.
But...
It's still a standard 1911 frame and it still has a standard slidestop crosspin and it still has standard lower lug feet on the barrel. Using a 24-pound action/recoil spring still represents a 50% increase in impact momentum over the 16-pound spring...and going by the original specs...even a 16 pounds is overspringing the slide a bit.
The slide's forward momentum is essentially brought to a sudden stop by the lower lug feet hitting the slidestop pin...which in turn impacts its mounting holes in the frame. Those lower lug feet are pretty small, and the frame walls that the pin passes through are fairly thin. The lug feet can be pounded and deformed and the holes elongated earlier under 50% more more impact than they were designed to handle in the long term. It's also possible for a vertical crack to form adjacent to the bottom of the holes. I've seen it a few times in LW Commanders with as few as 5,000 rounds down the pipe from shooters using 20 pound springs in the mistaken belief that they're "saving" the frame.
The impact abutment was designed to take the impact. The lower lug feet and the slidestop holes, not so much.
Using overly strong action/recoil springs doesn't keep the gun from breaking. It only changes the place that it breaks. There just ain't any such thing as a free lunch.
OP
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ugaarguy
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TR, come back when you get everything installed, and let us know you like the new setup. I think you'll be impressed.
Tuner, you think a square bottom stop, stock mainspring, and dropping to 14lb recoil spring would increase life on a SA full size lightweight in .45 ACP?
Tuner, you think a square bottom stop, stock mainspring, and dropping to 14lb recoil spring would increase life on a SA full size lightweight in .45 ACP?
1911Tuner
Moderator Emeritus
Don't know about increasing the life of the gun to any appreciable degree. The frame isn't the concern anyway. It's the slide that takes the real pounding and the spring has no bearing on that. The slide and barrel assembly is the gun. The frame is essentially no more than the gun mount and the housing for the controls.
There are reports of 1911s enduring tens of thousands of rounds, and wearing out multiple barrels. If the frames were all that fragile, they wouldn't do that with any reasonable spring rate. Far too much is made of "Frame Pounding" and I suspect that it was started by the people who are in the business to sell springs and shock buffers. You know...First convince the buyer that he "needs" it, and then sell it to him.
Back in the day when the 1911 was first adopted up to the mid 1940s, when GI contracts ended forever...the US Army ordered several slides and barrels...along with literally dozens of various other small parts...for each pistol delivered. Neither the slides nor the frames were heat-treated and hardened. Yet, the frames remained in service through multiple slide and barrel replacements...all the way up to the point that they were so badly worn out that you could almost field-strip one by shaking it vigorously.
I've rebuilt a number of these rattletrap frames, and after a little rail peening to reduce the vertical play, they all work fine. Oh, they're often cracked at the front of the rails, but that's really neither here nor there. Nature of the beast with sharp corners and thin cross-sections...and the cracks are self-limiting.
There are reports of 1911s enduring tens of thousands of rounds, and wearing out multiple barrels. If the frames were all that fragile, they wouldn't do that with any reasonable spring rate. Far too much is made of "Frame Pounding" and I suspect that it was started by the people who are in the business to sell springs and shock buffers. You know...First convince the buyer that he "needs" it, and then sell it to him.
Back in the day when the 1911 was first adopted up to the mid 1940s, when GI contracts ended forever...the US Army ordered several slides and barrels...along with literally dozens of various other small parts...for each pistol delivered. Neither the slides nor the frames were heat-treated and hardened. Yet, the frames remained in service through multiple slide and barrel replacements...all the way up to the point that they were so badly worn out that you could almost field-strip one by shaking it vigorously.
I've rebuilt a number of these rattletrap frames, and after a little rail peening to reduce the vertical play, they all work fine. Oh, they're often cracked at the front of the rails, but that's really neither here nor there. Nature of the beast with sharp corners and thin cross-sections...and the cracks are self-limiting.
1911Tuner
Moderator Emeritus
Thanks. I just try to point to the obvious and watch the light come on.
flightsimmer
Member
Quote; I made an exception buying this Delta, since all Delta Elites are Series 80. Ugaarguy
Huh!
That's the first time I've heard that. My stainless Colt, Delta Elite is a Series 70 model, Ser. # DS010XX. I pre-ordered it before they were ever released for sale.
10mm, when you care enough to send the very best.
Huh!
That's the first time I've heard that. My stainless Colt, Delta Elite is a Series 70 model, Ser. # DS010XX. I pre-ordered it before they were ever released for sale.10mm, when you care enough to send the very best.
1911Tuner
Moderator Emeritus
You might want to look a little closer. The Delta Elite came along in 1987...four years after the introduction of the Series 80s. Unless you special-ordered it from the custom shop...and by that point, Colt didn't likely have any pre-80 slides and frames left...it's probably a Series 80.
flightsimmer
Member
I stand corrected. I just went out and re-examined it and it is a series 80. I've got so many 1911 models that I get them confused I guess.
10mm, when you care enough to send the very best.
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TexasRifleman
Moderator Emeritus
Good thing is it's a 5 minute job to turn them all back into Series 70 
That's the first thing I do when I get a Series 80..... take all that plunger out and grind the little thing-a-ma-jig down round so it's just a spacer. Not on a carry gun of course.
Got my squared off FP stop from Midway today, and a new heavy mainspring, can't wait to try this out.
Tuner (and others) I have another question though. My Delta has been using a full length guide rod since the day I got it. I threw the Colt short plug and double spring in the trash literally the first day I had the gun.
While I had it all apart I figured I'd go back the original way so I ordered a standard 1911 guide rod and plug. When I put it back together it was very difficult to push the plug in far enough to turn the bushing. Is it possible that this plug is too long and needs a little hit with the Dremel? And, if it's too long what am I going to beat up shooting it like this? I got it in far enough for the bushing to turn but I wonder if I'm impeding the slide going all the way back somehow?
Does my question even make sense?
That's the first thing I do when I get a Series 80..... take all that plunger out and grind the little thing-a-ma-jig down round so it's just a spacer. Not on a carry gun of course.Got my squared off FP stop from Midway today, and a new heavy mainspring, can't wait to try this out.
Tuner (and others) I have another question though. My Delta has been using a full length guide rod since the day I got it. I threw the Colt short plug and double spring in the trash literally the first day I had the gun.
While I had it all apart I figured I'd go back the original way so I ordered a standard 1911 guide rod and plug. When I put it back together it was very difficult to push the plug in far enough to turn the bushing. Is it possible that this plug is too long and needs a little hit with the Dremel? And, if it's too long what am I going to beat up shooting it like this? I got it in far enough for the bushing to turn but I wonder if I'm impeding the slide going all the way back somehow?
Does my question even make sense?
1911Tuner
Moderator Emeritus
Hmm. Never ran into a plug too long. Too large in diameter or swelled/deformed maybe.
Run it in and out of the bare slide without the spring and see. Look for scraped areas on the finish for a clue as to what you've got.
Run it in and out of the bare slide without the spring and see. Look for scraped areas on the finish for a clue as to what you've got.
flightsimmer
Member
About this squared off EGW series 80 firing pin stop, I'm looking at Midways web site but I don't see a EGW, squared, series 80, 10mm firing pin stop much less a stainless one listed. They have (out of stock) EGW stops for 9mm and 38 Super series 80, 1911's and series 70 .45 ACP only, listed.
The firing pin stop in my stainless Delta Elite is rounded on the bottom where it contacts the hammer as the slide comes back to cock it.
It would seem that a stiffer mainspring might be more productive but a squared FP stop would seem to cause more wear on the FPS and the hammer as would the added main spring pressure on the guide rails.
I'll re-read this whole thread untill I feel I understand what everyone is getting at but at this point I'm just confused.
My Delta Elite is stock except for an adjustable (stop) trigger and a beaver tail grip safty and I've never noticed any problems with it. I do recall seeing some light peening on the firing pin block when I last detail striped it.
Bar-Sto fitted a new barrel to it and it shoots extreamly tight 1" groups exactly to point of aim at 25 yards.
10mm, when you care enough to send the very best.
The firing pin stop in my stainless Delta Elite is rounded on the bottom where it contacts the hammer as the slide comes back to cock it.
It would seem that a stiffer mainspring might be more productive but a squared FP stop would seem to cause more wear on the FPS and the hammer as would the added main spring pressure on the guide rails.
I'll re-read this whole thread untill I feel I understand what everyone is getting at but at this point I'm just confused.
My Delta Elite is stock except for an adjustable (stop) trigger and a beaver tail grip safty and I've never noticed any problems with it. I do recall seeing some light peening on the firing pin block when I last detail striped it.
Bar-Sto fitted a new barrel to it and it shoots extreamly tight 1" groups exactly to point of aim at 25 yards.
10mm, when you care enough to send the very best.
TexasRifleman
Moderator Emeritus
Well I may have ordered the wrong thing, this being new to me. I got Wilson "Square Bottom". I don't know if that's the same as the EGW or not. Hope I didn't get the wrong part.
Tuner said:
OK that's odd. Maybe it's not too long, it just feels that way. It's not going in far enough to lock in place with the bushing very easily, so something is hitting something, have to play with it and figure out what I've done.
kenhwind
Member
The Series 80 EGW .38 Super FPS is correct for the Delta Elite. The Wilson is not a true squared bottom like the EGW.
The square bottom firing pin stop does work as per Tuner's advice. As a matter of fact it worked so well in my Colt LWT GM that I found a warranty issue with my gun. The pistol worked just fine with the factory FPS (or so I thought). When I installed the EGW FPS the slide jammed open in a full recoil position. Why you ask! Colt did not bevel the inside rearward edge of the slide recoil spring tunnel and the recoil spring was getting squeezed in between the slide and RS guide. Tuner put his finger on this problem too.
Colt did bevel the slide, but not as much as I'm used to seeing. The pistol seems to be working fine now with the EGW firing pin stop re-installed. I didn't tell Colt that a modification showed a discrepency in their product.
After reading and posting in several threads I sold all of my other recoil springs on e-Bay and will now only use the correct ones.
The square bottom firing pin stop does work as per Tuner's advice. As a matter of fact it worked so well in my Colt LWT GM that I found a warranty issue with my gun. The pistol worked just fine with the factory FPS (or so I thought). When I installed the EGW FPS the slide jammed open in a full recoil position. Why you ask! Colt did not bevel the inside rearward edge of the slide recoil spring tunnel and the recoil spring was getting squeezed in between the slide and RS guide. Tuner put his finger on this problem too.
Colt did bevel the slide, but not as much as I'm used to seeing. The pistol seems to be working fine now with the EGW firing pin stop re-installed. I didn't tell Colt that a modification showed a discrepency in their product.
After reading and posting in several threads I sold all of my other recoil springs on e-Bay and will now only use the correct ones.
1911Tuner
Moderator Emeritus
Most people don't leave the corner dead square, but cut a light radius or a bevel. I use a 1/16th radius...but some do leave it square. I've had the firing pin stops in my two main beaters for something over 375,000 rounds about evenly split...with the OEM hammers. Never a problem.
The mainspring doesn't have any effect on the frame rails, and using a 25-pound spring is only 2 pounds above standard, so not much chance of damaging anything. The gun just isn't that fragile.
flightsimmer
Member
OK, I have re-read this entire thread now and if I have it right?
For the average shooter using hot factory loads, he would do well to replace the stock Colt firing pin stop with an Evolution Gun Works, EGW, Oversized Series 80 - 9mm/38 Super firing pin stop which does not come in stainless steel but it is hardened to Rockwell 48 Rc scale steel and must be fitted to the slide and very slightly radiused and polished on the edge that contacts the hammer.
Next, remove and replace the dual recoil spring pack with a single 15 lb. recoil spring and a standard G.I. spring guide and no buffer pad.
Then replace the hammer mainspring with a 25 lb. spring.
Then go to the range and try it out.
Have I got it right or not?
One last question, how would you measure the spring pressure(s) to be sure they are correct? It would seem that you would squeeze the spring down to it's mounted length on a scale and see how much pressure in lbs. is exerted on the scale, much like you would on a automotive valve spring tester I would think.
10mm, when you care enough to send the very best.
For the average shooter using hot factory loads, he would do well to replace the stock Colt firing pin stop with an Evolution Gun Works, EGW, Oversized Series 80 - 9mm/38 Super firing pin stop which does not come in stainless steel but it is hardened to Rockwell 48 Rc scale steel and must be fitted to the slide and very slightly radiused and polished on the edge that contacts the hammer.
Next, remove and replace the dual recoil spring pack with a single 15 lb. recoil spring and a standard G.I. spring guide and no buffer pad.
Then replace the hammer mainspring with a 25 lb. spring.
Then go to the range and try it out.
Have I got it right or not?
One last question, how would you measure the spring pressure(s) to be sure they are correct? It would seem that you would squeeze the spring down to it's mounted length on a scale and see how much pressure in lbs. is exerted on the scale, much like you would on a automotive valve spring tester I would think.
10mm, when you care enough to send the very best.
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1911Tuner
Moderator Emeritus
If you intend to shoot full house 10mm, you might want to go with an 18 pound recoil spring as per Ned Christiansen's research.
Zerstoerer
Member
Reading through all this wisdom - one question remains:
What do I do if my Colt Delta Elite works just fine the way it is?
It has a single recoil spring, some short stubby plastic (did Colt really make those?) recoil spring guide, so some previous owner must have already modified it from original.
Works great and I am looking for reliablity before anything else. Now you guys have me worried about 80 series parts, some different firing pin stop I don't even understand and timing issues...
The only thing I don't like is some kind of sticky feeling when pulling the slide back against the stop, which (I think) is because of the 'plastic' spring guide as compared to the solid metal clunk of a PT1911 with a full length (metal) spring guide.
If this is in fact the reason, I could see me changing this part to a metal version.
To make things even more confusing, here is a quote from the Wolff website:
"With the exception of recoil and magazine springs, all other springs offered by W.C. Wolff Company for use in 1911 and Commander series pistols (Hammer Springs, Magazine Catch Springs, Sear Spring, Plunger Tube Spring, Firing Pin Springs, Firing Pin Safety Springs) are the same for the Delta Elite 10mm pistol".
I would think the folks at Wolff know a thing or two about springs, so what is up with the 'main spring' being the same to all other 1911s?
What do I do if my Colt Delta Elite works just fine the way it is?
It has a single recoil spring, some short stubby plastic (did Colt really make those?) recoil spring guide, so some previous owner must have already modified it from original.
Works great and I am looking for reliablity before anything else. Now you guys have me worried about 80 series parts, some different firing pin stop I don't even understand and timing issues...
The only thing I don't like is some kind of sticky feeling when pulling the slide back against the stop, which (I think) is because of the 'plastic' spring guide as compared to the solid metal clunk of a PT1911 with a full length (metal) spring guide.
If this is in fact the reason, I could see me changing this part to a metal version.
To make things even more confusing, here is a quote from the Wolff website:
"With the exception of recoil and magazine springs, all other springs offered by W.C. Wolff Company for use in 1911 and Commander series pistols (Hammer Springs, Magazine Catch Springs, Sear Spring, Plunger Tube Spring, Firing Pin Springs, Firing Pin Safety Springs) are the same for the Delta Elite 10mm pistol".
I would think the folks at Wolff know a thing or two about springs, so what is up with the 'main spring' being the same to all other 1911s?
OP
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ugaarguy
Member
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The mainspring is also referred to as the hammer spring by some.
The original GI 1911s used a short metal recoil spring guide. The Colt original part on the Delta Elite was plastic, but was a smaller diameter to fit the inner spring of the dual recoil spring.
Listen to Tuner. Ignore my comments about the S80 parts - I'm weird about them. The timing is also related to the Series 80 parts. I basically understand it, but not well enough to explain it like Tuner can.
The firing pin stop is the little plate on the back of the slide which holds the firing pin into the slide. If you look at the bottom of the FP stop it's radiused. The EGW oversize stop is left squared off on the bottom so that the end user can select however much (or little) radius to put on it.
1911Tuner
Moderator Emeritus
The small radius on the firing pin stop adds a little delay to the slide. Not much, but when things are moving fast, a little change can have a large effect. It does this by lowering the stop's contact point with the hammer, reducing mechanical advantage in accelerating the hammer. The resistance...the outside force...comes from the mainspring's load and the hammer's inertial mass. Those things must be overcome, and there's only so much driving force and momentum available. The more of it that's expended in overcoming the hammer's movement...the less there is left to keep the slide moving.
By delaying the slide that extra bit, it puts the bullet farther along in the barrel relative to the slide's position, and the bullet escapes earlier...relative to the slide's position...which removes the accelerating forces from the slide earlier. Think of it like a drag race driver stabbing the brake just as he launches the car. Once that momentum is lost, it can't be regained...so the slide is moving slower as it compresses the spring...and slower when it hits the impact abutment. Lower velocity means lower momentum...and impact momentum is what flips the muzzle.
Much is made of the short variants requiring heavy springs in order to keep the slide from hitting the frame "too hard"...but that comes from a basic misunderstanding of the physics involved and of the mechanics of the gun itself. Mostly, it's a misunderstanding of the spring's true function. The spring is there to return the slide...not to decelerate it. That it does do that is incidental.
It's moving faster because of its lower mass...but with the recoil spring removed from both pistols...the 5-inch and the 3-inch...it will hit no harder. It can't. Momentums are equal in both directions. It can't have more momentum than the bullet, even though it's moving faster than the more massive slide...and momentum is what whacks the frame and causes it to move.
In reality, the short, low mass slide probably doesn't hit the frame as hard, all else assumed to be equal. The shorter barrel causes a velocity loss, and because momentums are equal and momentum is a function of Mass X Velocity...the short slide has less momentum than the 5-inch gun.
And to expound further...With equal springs...equal outside force...the short slide will still hit with less impact momentum.
The lower the mass, the faster it decelerates when it encounters a given outside force. More...the higher the velocity of a given mass...the harder a given outside force fights it, and the faster the moving mass is decelerated faster.
Timing:
There will be no timing issues. Springs don't affect timing. Timing is mechanically fixed and the timed function will occur at the appointed place, regardless of how fast or slow the machine runs. Springs affect time, which is a function of speed and distance.
By delaying the slide that extra bit, it puts the bullet farther along in the barrel relative to the slide's position, and the bullet escapes earlier...relative to the slide's position...which removes the accelerating forces from the slide earlier. Think of it like a drag race driver stabbing the brake just as he launches the car. Once that momentum is lost, it can't be regained...so the slide is moving slower as it compresses the spring...and slower when it hits the impact abutment. Lower velocity means lower momentum...and impact momentum is what flips the muzzle.
Much is made of the short variants requiring heavy springs in order to keep the slide from hitting the frame "too hard"...but that comes from a basic misunderstanding of the physics involved and of the mechanics of the gun itself. Mostly, it's a misunderstanding of the spring's true function. The spring is there to return the slide...not to decelerate it. That it does do that is incidental.
It's moving faster because of its lower mass...but with the recoil spring removed from both pistols...the 5-inch and the 3-inch...it will hit no harder. It can't. Momentums are equal in both directions. It can't have more momentum than the bullet, even though it's moving faster than the more massive slide...and momentum is what whacks the frame and causes it to move.
In reality, the short, low mass slide probably doesn't hit the frame as hard, all else assumed to be equal. The shorter barrel causes a velocity loss, and because momentums are equal and momentum is a function of Mass X Velocity...the short slide has less momentum than the 5-inch gun.
And to expound further...With equal springs...equal outside force...the short slide will still hit with less impact momentum.
The lower the mass, the faster it decelerates when it encounters a given outside force. More...the higher the velocity of a given mass...the harder a given outside force fights it, and the faster the moving mass is decelerated faster.
Timing:
There will be no timing issues. Springs don't affect timing. Timing is mechanically fixed and the timed function will occur at the appointed place, regardless of how fast or slow the machine runs. Springs affect time, which is a function of speed and distance.
Zerstoerer
Member
Thanks for the explanation - there sure is a lot of physics going on in an 'dumb old fourtyfive'.
So I guess I need a larger diameter, metal guide rod to replace the original plastic Colt one because the previous owner did switch to a single spring?
What is a good source for this part? We'll see if that gets rid of the sticky
feeling.
Thanks.
So I guess I need a larger diameter, metal guide rod to replace the original plastic Colt one because the previous owner did switch to a single spring?
What is a good source for this part? We'll see if that gets rid of the sticky
feeling.
Thanks.
OP
OP
ugaarguy
Member
- Joined
- Mar 19, 2006
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- 13,828
TexasRifleman
Moderator Emeritus
Well I managed to sneak out a couple of hours this morning and shoot a little, including 75 or so rounds through this Delta. I was shooting some old Georgia Arms reman stuff I had, so it's not Norma 10mm hot, but a bit more than IPSC major so a good middle of the road load I think.
Seemed to work pretty good. I really like having a lighter recoil spring, makes manipulation a lot better. Functioned 100% and didn't throw the brass a mile away so I guess it's OK? Not sure what to check to see if I'm hurting anything though.
When I got home I took the gun apart to clean it and it went back together without the problems I had before so that recoil spring plug must simply have been tight and needed some breaking in. Dunno. Could barely get it in over the weekend and today I could do it without a bushing wrench so that's good.
I guess I'm good to go, just wonder if there's something I should look for to make sure I'm not beating the gun to death.
Seemed to work pretty good. I really like having a lighter recoil spring, makes manipulation a lot better. Functioned 100% and didn't throw the brass a mile away so I guess it's OK? Not sure what to check to see if I'm hurting anything though.
When I got home I took the gun apart to clean it and it went back together without the problems I had before so that recoil spring plug must simply have been tight and needed some breaking in. Dunno. Could barely get it in over the weekend and today I could do it without a bushing wrench so that's good.
I guess I'm good to go, just wonder if there's something I should look for to make sure I'm not beating the gun to death.
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